The purpose of this grant application is to confirm and extend our recent discovery that exposure to a terrestrial optic flow specifying forward translation can elicit air stepping in human newborns. This intriguing finding suggests that the human infant is biologically prepared at birth to regulate locomotion on the basis of visual information. The primary question asked in the present application concerns the specificity of such precocious visual-locomotor coupling. The question has three interrelated components. The first component asks whether the quantity and quality of stepping movements vary as a function of the type of optic flow to which the infant is exposed. The second component addresses whether the stepping movements vary as a function of the velocity of the optic flow (i.e., whether there is already some degree of scaling between vision and locomotion at birth). The third question addresses whether there is continuity across the first few weeks of life in the infants' reaction to the optic flow. Ultimately, this line of research has the potential to offer valuable insights into the continuity of the developmental process. Aside from the theoretical insights that can be gained into the nature of perceptual-motor development, addressing these questions enables us to tackle the larger practical goal of designing a paradigm to diagnose problems in visual-motor coupling at birth. At this time, sensitivity to optic flows and the relation of such sensitivity to motor activity have not been studied in very young infants. However, any problems in this coupling could have serious consequences for the infant's perceptual, motor, cognitive, and social development. Presently, there is no visual or motor examination that would allow the clinician to test the newborn's sensitivity to visual proprioception. Yet, such a test would permit the identification of babies who have mild or moderate visual or motor impairments so that interventions could be started at ages much earlier than at present. [unreadable] [unreadable]